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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
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Journal DOI :
The Korean Society of Automotive Engineers
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Nov 2007
Volume 15, Issue 5 - Sep 2007
Volume 15, Issue 4 - Jul 2007
Volume 15, Issue 3 - May 2007
Volume 15, Issue 2 - Mar 2007
Volume 15, Issue 1 - Jan 2007
Selecting the target year
The Effect of Injection Angle and Nozzle Diameter on HCCI Combustion
Kook, Sang-Hoon ; Kong, Jang-Sik ; Park, Se-Ik ; Bae, Choong-Sik ; Kim, Jang-Heon ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 1~7
The effect of injector geometries including the injection angle and number of nozzle holes on homogeneous charge compression ignition (HCCI) engine combustion has been investigated in an automotive-size single-cylinder diesel engine. The HCCI engine has advantages of simultaneous reduction of PM and NOx emissions by achieving the spatially homogenous distribution of diesel fuel and air mixture, which results in no fuel-rich zones and low combustion temperature. To make homogeneous mixture in a direct-injection diesel engine, the fuel is injected at early timing. The early injection guarantees long ignition delay period resulting in long mixing period to form a homogeneous mixture. The wall-impingement of the diesel spray is a serious problem in this type of application. The impingement occurs due to the low in-cylinder density and temperature as the spray penetrates too deep into the combustion chamber. A hole-type injector (5 holes) with smaller angle (
) than the conventional one (
) was applied to resolve this problem. The multi-hole injector (14 holes) was also tested to maximize the atomization of diesel fuel. The macroscopic spray structure was visualized in a spray chamber, and the spray penetration was analyzed. Moreover, the effect of injector geometries on the power output and exhaust gases was tested in a single-cylinder diesel engine. Results showed that the small injection angle minimizes the wall-impingement of diesel fuel that results in high power output and low PM emission. The multi-hole injector could not decrease the spray penetration at low in-cylinder pressure and temperature, but still showed the advantages in atomization and premixing.
HCCI Combustion of DME in a Rapid Compression and Expansion Machine
Sung, Yong-Ha ; Jung, Kil-Sung ; Choi, Byung-Chul ; Lim, Myung-Taeck ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 8~14
Compression ignition of homogeneous charges in IC engines indicates possibilities of achieving the high efficiency of DI diesel engines with low level of NOx and particulate emissions. The objectives of this study are to further understand the characteristics of the HCCI(Homogeneous charge compression ignition) combustion and to find ways of extending the rich HCCI operation limit in an engine-like environment. DME fuel is supplied either in the form of premixture with air or directly injected in the combustion chamber of a rapid compression and expansion machine under the conditions of various equivalence ratio and injection timing. The cylinder pressure is measured and the rate of heat release is computed from the measured pressure for the analysis of the combustion characteristics. The experimental data show that the RCEM can operate without knock on mixtures of higher equivalence ratio, when DME is directly injected in the combustion chamber than introduced as a fraction of a perfect or nearly perfect premixture. Very early fuel injection timings usually employed in HCCI operation are seen to have only insignificant effects in control of ignition timing.
The Effects of Hydrogen on DME HCCI Combustion
Baek, Cheul-Woo ; Yoon, Hyeon-Sook ; Yeom, Ki-Tae ; Jang, Jin-Young ; Bae, Choong-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 15~21
The aim of this paper is controlling ignition timing and load in homogeneous charge compression ignition (HCCI) combustion with low cetane number fuel, hydrogen. Homogeneous charge compression ignition (HCCI) combustion is an advanced combustion technology that achieves higher thermal efficiency and lower
emissions than that of conventional combustion system. Dimethyl ether (DME), which has been researched widely as the most attractive alternative fuel of diesel, is attractive for HCCI combustion because of the easy evaporation. In this study, the single cylinder DME engine operated with a direct injection system has been used to investigate combustion processes and emissions of DME HCCI with a premixed hydrogen supply. The experiment was carried out under various engine speed and fraction rates of hydrogen. As a result, the increase of fraction rates of hydrogen retard the DME ignition timing and eliminated the knocking during high engine speed condition. IMEP was increased with increase of fraction rates of hydrogen by 30%. 40% of the fraction rates of hydrogen resulted in misfiring. The
emission was reduced by increasing the fraction rates of hydrogen, but HC emission was increased.
A Study on the Characteristics for Durability with Biodiesel Fuel(BDF 5%) in a Commercial Common Rail Diesel Engine
Choi, Seung-Hun ; Oh, Young-Taig ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 22~27
Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. CRDI(common rail direct injection) diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. In this study, a common rail diesel engine was run with 5% of biodiesel fuel(BDF 5%) more than 150 hours. Engine dynamometer testing was completed at regularly scheduled intervals to investigate the engine performance and exhaust emissions. The data of engine performance and exhaust emissions was sampled at 1 hour intervals for analysis. When a common rail diesel engine runs on BDF 5% for long time, power and energy consumption of the engine are similar to the case using diesel fuel. The smoke emission of BDF 5% was reduced in comparison with diesel fuel, that is, it was reduced approximately 15% at 4000rpm, and load of 90%. And, CO and
were reduced, too. On the other hand, NOx emission of biodiesel fuel was slightly increased about 2%, but it was almost same as a commercial diesel fuel.
Durability Analysis and Experiments of a Vehicle Component
Park, Dong-Woon ; Park, Su-Jin ; Yoo, Wan-Suk ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 28~34
In design stage of vehicles, the application of virtual durability analysis techniques enables us to cut down the necessary time and cost to carry out various physical experiments. In this study, computer simulations of vehicle suspensions were carried out with DADS program including component flexibility, and the durability analysis of vehicle components was executed with MSC/Fatigue program using the load history obtained from vehicle dynamic simulation. Driving test of a vehicle was also carried out to obtain precise input data for the durability analysis, and the results of virtual durability analysis were compared to those of experiments.
A Study on the Fluid Network Analysis for the LPG Supply System of the Gaseous Fuel Injection Type
Yun, Jeong-Eui ; Kim, Myung-Hwan ; Nam, Hyeon-Sik ; Jeong, Tae-Hyuung ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 35~40
The gaseous fuel injection (GFI) type in LPG fuel supply system has more advantage than the liquified fuel injection type from the viewpoint of durability and cost reduction. But in GFI system, to control pressure and temperature of gaseous fuel is needed to get precision fuel metering for the compressible characteristic of gaseous fuel. In this study, the effects of pressure and temperature on the fuel metering was simulated by commercial flow network analysis package, Flowmaster. And the fuel composition effects on the fuel metering were also studied to figure out the fuel metering characteristics.
Foam Filling Effect on Bending Collapse Characteristics for Member Section Type
Lee, Il-Seok ; Kang, Sung-Jong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 41~49
More diversified and strengthened safety regulations require higher safety vehicle with less weight. The structural foam can play a role for restraining section distortion of main body members undergoing bending collapse at vehicle crash. In this study, using structural foam modeling technology, validated in previous work, the bending collapse characteristics were evaluated for two types of circular and actual vehicle body frame sections. With changing the foam filling method, outer panel thickness and section shape, load carrying capability and absorbed energy were observed. The results indicate valuable design strategy for effectively elevating bending collapse performance of body members with foam filled.
Study on Discomfort of Vertical Whole-body Shock Vibration Having Various Magnitudes, Frequencies and Damping
Ahn, Se-Jin ; Griffin, Michael J. ; Yoo, Wan-Suk ; Jeong, Weui-Bong ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 50~57
Shocks are excited by impulsive forces and cause discomfort in vehicles. Current standards define means of evaluating shocks and predicting their discomfort, but the methods are based on research with a restricted range of shocks. This experimental study was designed to investigate the discomfort of seated subjects exposed to a wide range of vertical shocks. Shocks were produced from the responses of one degree-of-freedom models, with 16 natural frequencies (from 0.5 to 16 Hz) and four damping ratios (0.05 0.1, 0.2 and 0.4), to a hanning-windowed half-sine force inputs. Each type of shock was presented at five vibration dose values in the range
. Fifteen subjects used magnitude estimation method to judge the discomfort of all shocks. The exponent in Stevens' power law, indicating the rate of growth in discomfort with shock magnitude, decreased with increasing fundamental frequency of the shocks. At all magnitudes, the equivalent comfort contours showed greatest sensitivity to shocks having fundamental frequencies in the range 4 to 12.5 Hz. At low magnitudes the variations in discomfort with the shock fundamental frequency were similar to the frequency weighting
in BS 6841, but low frequency high magnitudes shocks produced greater discomfort than predicted by this weighting. At some frequencies, for the same unweighted vibration dose value, there were small but significant differences in discomfort caused by shocks having different damping ratios. The rate of increase in discomfort with increasing shock magnitude depends on the fundamental frequency of the shock. In consequence, the frequency-dependence of discomfort produced by vertical shocks depends on shock magnitude. For shocks of low and moderate discomfort, the current methods seem reasonable, but the response to higher magnitude shocks needs further investigation.
A Study on the Characteristics of Carbon Dioxide Emissions from Gasoline Passenger Cars
Lyu, Young-Sook ; Ryu, Jung-Ho ; Jung, Sung-Woon ; Jeon, Min-Seon ; Kim, Dae-Wook ; Eom, Myung-Do ; Kim, Jong-Choon ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 58~64
As the concerns regarding global worming were increased, the pressure of greenhouse gas(GHG) emission reduction on mobile source was also increased. Carbon dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this
emission. Therefore automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. In this study, in order to investigate
emission characteristics from gasoline passenger cars(PC), which is the most dominant vehicle type in Korea, 106 vehicles were tested on the chassis dynamometer.
emissions and fuel efficiency were measured. The emission characteristics by displacement, gross vehicle weight, vehicle speed and CVS-75/vehicle speed mode were discussed. Test modes were vehicle speed modes and CVS-75 mode that have been used to develop emission factors and to regulate for light-duty vehicle in Korea. It was found that
emissions showed higher large displacement, heavy gross vehicle weight, low vehicle speed and CVS-75 mode than small displacement, light gross vehicle weight, high vehicle speed and vehicle speed mode, respectively. From these results, correlation between
emission and fuel efficiency was also determined. The results of this study will contribute to domestic greenhouse gas emissions calculation and making the national policy for climate change.
The Effect of EGR Pipe Configuration on EGR Characteristics of Diesel Engine with Variable Geometry Turbocharger
Jeong, Soo-Jin ; Chung, Jae-Woo ; Kang, Jeong-Ho ; Kang, Woo ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 65~73
The use of an Exhaust Gas Recirculation(EGR) for a diesel engine with variable geometry turbocharger(VGT) has confronted how to obtain the amount of EGR for NOx reduction requirement at wide operating range and less side effect. Through a combined effort of modeling(wave action simulation) and experiment, an investigation into the effect of EGR area ratio and pipe length on EGR characteristics of common rail diesel engine with VGT has been performed. For accurate computation, calibration of constants involved in empirical and semi-empirical correlations has been performed at a specific operating point, before of its use for engine simulation. From the results of this study, it was found that EGR rate is sharply increased with increasing EGR area ratio until area ratio of 0.3. However, the effect of EGR area ratio on EGR rate is negligible beyond this criteria. This study also investigates the effect of EGR pipe length on a EGR amount and pulsating flow characteristics at EGR junction. The results showed that the longer EGR pipe length, the lower EGR amount was achieved due to the flow loss resulting in lower amplitude of pressure wave.
Combustion and Exhaust Emission Characteristics of DME in a Common-rail Diesel Engine
An, Sang-Gyu ; Kim, Myung-Yoon ; Yoon, Seung-Hyun ; Lee, Je-Hyung ; Lee, Chang-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 74~80
An experiment was conducted with a common-rail direct injection diesel engine operated with neat dimethyl ether (DME). In order to investigate the effect of combustion characteristics and emission reduction of DME fuel, the experiment was performed at various injection pressure from 35 MPa to 50MPa. Also, the exhaust emissions from the engine were compared with that of diesel fuel. In this work, Cooled EGR was implemented to reduce
exhaust emissions. The results showed that DME has shorter ignition delay than that of diesel fuel. Despite of the increased
emissions with DME at an equal engine power compared to the case of fueling diesel, the engine emitted zero soot emissions all over the operating conditions in this work.
emission can be decreased greatly by adopting 45% of EGR while maintaining zero soot emission. Judging from the result of engine test, DME is a suitable fuel for common-rail diesel engine due to it's clean emission characteristics.
Rational Reduction of the Number of Spot Welds in the Vehicle Body Considering Durability
Choi, Noo-Ri ; Ju, Byeong-Hyeon ; Byun, Hyung-Bai ; Kim, Dong-Seok ; Lee, Byung-Chai ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 81~86
We suggest a design method for reducing the number of spot welds in the vehicle body in terms of durability. To reduce the number of spot welds, we use the DOE(Design of Experiments) analysis with two influence indices for the durability and the fatigue life of a spot weld itself. Through the suggested design method, we select spot welds that could be removed without serious reduction of durability of the whole model. We apply this new methodology to the BIW(Body In White) model of a vehicle by choosing some practical parts where durability-related point of view must be considered importantly by experience.
Heat Transfer Characteristics according to the Tube Arrangement of Bundle Type Plastic Oil Cooler
Heo, Hyung-Seok ; Bae, Suk-Jung ; Kim, Hyun-Chul ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 87~94
It has been argued that the use of plastics can cause problems during design and manufacture owing to their low strength, relatively poor thermal conductivity and large thermal expansion. However, the advantages of plastics e.g., corrosion resistance, low cost, curtailment of weight, design flexibility etc., can compensate abundantly for the disadvantages. This study analyzes and compares the heat transfer performance characteristics of automotive compact oil cooler composed of plastic tube bundle with conventional metal oil cooler on the same core area basis as diameter, tube thickness, number of tube or tube arrangement varies. The performance analyses are accomplished by use of computational fluid dynamics program Fluent 6.2, which is verified and compared with the results of performance tests. The result of analyses is coincided with that of experiments. Flow pattern at air side according to tube arrangement is dominant factor which affects heat dissipation in case of similar total heat transfer surface area.
An Experimental Study on In-Plate Evaporation Heat Transfer and Flow Characteristics for Automobile
Kwak, Kyung-Min ; Joo, Sang-Woo ; Jung, Woo-Youl ; Kim, Taek-Keun ; Kim, Kwang-Il ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 95~100
An experimental study was performed to evaluate the in-plate evaporation heat transfer and flow characteristics of a evaporator used in automobile. Two test-cores with different heat transfer area, bead-shape and bead-array were tested, A type and B type. For the heat transfer, Nusselt number for B type test-core reaches a value nearly equal to the one for A type test-core, in the whole range of equivalent Reynolds number. But, for the same mass flow rate of refrigerant, hA for B type test-core becomes higher with the increase of the mass quality of refrigerant than for A type test-core. In a flow visualization experiment, the wake zone of refrigerant circulating at u-turn position of plate is observed.
Analysis of Piezoelectric Ceramic Multi-layer Actuators Based on the Electro-mechanical Coupled Meshless Method
Kim, Hyun-Chul ; Guo, Xianghua ; Kim, Won-Seok ; Fang, Daining ; Lee, Jung-Ju ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 101~108
This paper presents an efficient meshless method for analyzing cracked piezoelectric structures subjected to mechanical and electrical loading. The method employs an element free Galerkin (EFG) formulation and an enriched basic function as well as special shape functions that contain discontinuous derivatives. Based on the moving least squares (MLS) interpolation approach, The EFG method is one of the promising methods for dealing with problems involving progressive crack growth. Since the method is meshless and no element connectivity data are needed, the burdensome remeshing procedure required in the conventional finite element method (FEM) is avoided. The numerical results show that the proposed method yields an accurate near-tip stress field in an infinite piezoelectric plate containing an interior hole. Another example is to study a ceramic multilayer actuator. The proposed model was found to be accurate in the simulation of stress and electric field concentrations due to the abrupt end of an internal electrode.
Calculation of Brake Onset Velocity for Non-ABS Vehicle on Dry Asphalt Pavement
Kim, Kee-Nam ; Ok, Jin-Kyu ; Kim, Min-Seok ; Mun, Won-Kil ; Park, Su-Jin ; Yoo, Wan-Suk ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 109~114
Skid mark and coefficient of friction are usually utilized to calculate the velocity and behavior of vehicles. For a critical case such as traffic accident reconstruction, however, the initial velocity of the car should be calculated precisely. In this study, the skid marks on dry asphalt pavement were measured, and the velocity at brake onset was precisely recovered. A passenger car with new tires and non-contact optical speedometer were set up for the tests. A new methodology to determine the more precise velocity for Non-ABS vehicle at braking onset were suggested.
A Study on Effect of Quill Accumulator upon Performance of Motor-driven Cylinder Lubricator in a Large Two-stroke Diesel Engine
Bae, Myung-Whan ; Ok, Hyun-Jin ; Jung, Hwa ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 115~125
Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, a motor-driven cylinder lubricator for a large two-stroke marine diesel engine manufactured by
Switzerland Co., Ltd. was first developed by authors through the joint research of industry-university in 2002. The characteristic of the developed product is that can control automatically the oil feed rate to a load fluctuation by the motor drive and the offset cam. The performance of the product is not also inferior to the conventional one. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and improve the performance of a cylinder lubricator. In this study, the effect of quill with and without accumulator on maximum discharge pressure, delivery delay duration and oil feed rate relative to motor revolution speed using plunger stroke as a parameter is experimentally investigated by using the developed cylinder lubricator. It is found that the maximum discharge pressure with accumulator is higher than that of no accumulator as plunger stroke and motor revolution speed are elevated, and the delivery delay duration with accumulator is shorter than that of no accumulator as plunger stroke and motor revolution speed are increased. Also, oil feed rate with accumulator is less than that of no accumulator except for a plunger stroke of 2 mm as plunger stroke and motor revolution speed are raised.
The DOE Based Robust Design to Reduce the Brake Squeal Noise
Kwon, Seong-Jin ; Kim, Mun-Sung ; Lee, Bong-Hyun ; Lee, Dong-Won ; Bae, Chul-Yong ; Kim, Chan-Jung ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 126~134
Although there has been substantial research on the squeal noise for the automotive brake system, robust design issues with respect to control factors equivalent to design variables in optimization, noise factors due to system uncertainties, and signal factors designed to accommodate a user-adjustable setting still need to be addressed. For the purpose, the robust design applied to the disk brake system has been investigated by DOE (Design of Experiments) based Taguchi analysis with dynamic characteristics. The specific goal of this methodology is to identify a design with linear signal-response relationship, and variability minimization. The finite element models of the disk brake assembly have been constructed, and the squeal noise problems have been solved by complex eigenvalue analysis. As the practical robust design to reduce the brake squeal noise, material properties of pad, disk, and backplate, thickness and geometry of pad are selected as control factors, material properties of pad and disk, and the contact stiffness have been considered as noise factors, and friction coefficient between pad and disk is chosen as a signal factor. Through the DOE based robust design, the signal-to-noise ratio and the sensitivity for each orthogonal array experiment have been analyzed. Also, it has been proved that the proposed robust design is effective and adequate to reduce the brake squeal noise.
A Study on Influence of the Impact Direction on the Neck Injury during Low Speed Rear Impacts
Jo, Hui-Chang ; Kim, Young-Eun ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 135~142
MADYMO human model with the detail neck was used to investigate the reaction force of neck and neck injury from rear impact directions. In the validation simulation, head acceleration, thorax acceleration and the global kinematics of the head and neck were correlated well with experimental data. Acceleration data from three 15 km/h low speed car rear impact pendulum tests(rear-end, offset, oblique) were used to simulate the model. In the simulation results, the reaction force on the facet joint and discs in the oblique rear impact were higher than rear-end, offset rear impacts. Further research is still needed in order to neck injury analysis about different crash parameters.
A Study on Engine Oil Consumption Considering Wear of Piston-Ring and Cylinder Bore
Chun, Sang-Myung ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 143~150
Ring and cylinder bore wear may not be a problem in most current automotive engines. However, a small change in ring face and cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blow-by and oil consumption in an engine. Therefore, by predicting the wear of piston ring face and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Here, the oil amount through top ring gap into combustion chamber is estimated as engine oil consumption. Furthermore, the wear theories of ring and cylinder bore are included. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. The wear data of rings and cylinder bore are obtained from three engines after engine durability test. The calculated wear data of each part are turn out to be around the band of averaged test values or a little below. It is shown that the important factor regarding oil consumption increasement is the wear of ring face.
Filtration Characteristics of Metal Foam Filters for DPF Combined with Electrostatic Precipitation Mechanism
Park, Seok-Joo ; Lee, Dong-Geun ; Kim, Jin-Hyun ; Cho, Gyu-Baek ; Kim, Hong-Suk ; Jeong, Young-Il ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 151~158
Filtration studies, using simulated test nanoparticles or diesel nanoparticles, have been performed about Inconel foam filters for DPF combined with electrostatic precipitation. The simulated test particles were synthesized by laser ablation in the nitrogen atmosphere at the standard condition. The diesel particles were exhausted from the diesel engine driven on the condition of idle or load mode. Filtration efficiency of the metal foam filter is very low because most of particles are penetrated through the large pores of filter. However, the efficiency was considerably improved by applying the electric field to the filter and/or charging the nanoparticles. Nevertheless, the pressure drop of filter hardly increased because the filter-pores were not clogged by deposited particles and kept open.
Safety Evaluation of the Adaptive Cruise Control System
Yong, Boo-Joong ; Shim, So-Jung ; Yoon, Kyong-Han ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 159~164
The Advanced Safety Vehicle (ASV) allows drivers not only convenience and safety, but also many useful services provided by the Telematics technology. Since ASV is expected to be widely used in the near future, it is necessary to ensure the safety of ASV systems. Among several aspects of ASV, this paper investigates the safety of the Adaptive Cruise Control (ACC) system. Field tests are carried out under the domestic roadway and traffic conditions, according to International Standard Organization (ISO) requirements for ACC. The test data are analyzed whether the requirements are adequate for domestic circumstances, and the suggestions for findings are given.
A Design Compensation for Stable Flow/Pressure Control of Variable Displacement Type Piston Pump
Jung, Dong-Soo ; Kim, Hyoung-Eui ; Kang, E-Sok ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 165~174
Variable displacement type piston pump uses various controllers for controlling more than one state quantity like pressure, flow, power, and so on. These controllers need the mathematical model closely expressing dynamic behavior of pump for analyzing the stability of control systems which usually use various kinds of state variables. This paper derives the nonlinear mathematical model for variable displacement type piston pump. This model consists of two 1st oder differential equations by the continuity equations and one 2nd oder differential equation by the motion equation. To simplify the model we obtain the linear state variable model by differentiating the three nonlinear equations. And we verify this linearized model by comparison of simulation with experimentation and analyze the stability for the flow/pressure control. Finally this paper suggests the design compensation to ensure the stability of the systems.
Formability of Aluminum 5182-Polypropylene Sandwich Panel for Automotive Application
Kim, Kee-Joo ; Jeong, Hyo-Tae ; Sohn, Il-Seon ; Kim, Cheol-Woong ; Kim, Joong-Bae ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 175~181
The objective of this study was to develop formability evaluation techniques in order to apply aluminum sandwich panel for automotive body parts. For this purpose, newly adopting formability evaluation (using limit dome height and plane strain test) was carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the aluminum sandwich panel. The results showed that there were good agreements between the old formability evaluation method and the new method which was more simplified than that of old one. From the results of these formability evaluation, the formability of sandwich panel was higher than that of aluminum alloy sheet alone which was the skin component for the sandwich panel. Also, it was found that sandwich panel could reduce the weight and could have the same flexural rigidity simultaneously when it was compared to the automotive steel sheet.
Performance Characteristics of Electric Powertrain Parts for Power Split Type HEV at Steady Speed
Kim, Chai-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 15, issue 2, 2007, Pages 182~186
This paper studied performance characteristics of hybrid automotive to replace existing fossil fuel vehicles. Specially, about power split type HEV that is T-HEV's drive system when a vehicle drives at steady speed, monitored both output of each engine, motor and generator and battery SOC (state of charge) and analyzed performance characteristic of power transmission system and electricity power parts. This study shows those that acquired and analyzed information from signals between HCU and each controller of actual T- vehicle. From this study, it is confirmed that each conditions of EV and HEV drive can be a improvement with respect to the fuel efficiency of vehicles.